The basis of his work seems to have been Captain Thomas Hutchins’s, _A Topographical Description of Pennsylvania, Maryland, and Virginia_, published in London in 1778. Captain Hutchins was an American, who had seen much service in the English army before the Revolution, mainly as engineer. At the outbreak of the war he was in London, and owing to his sympathy for his native country, suffered indignities and imprisonment, but found an opportunity to publish his book. Escaping to America, he was in 1781, by the influence of Benjamin Franklin, made “Geographer to the United States of America,” which appears to have meant that he was in charge of the government surveys. After the war he lived in Philadelphia, but was well known in Pittsburgh where he often stopped, as he owned considerable land in Allegheny County. These facts and the knowledge that he died in Pittsburgh on April 28, 1789, no doubt helped to draw Cramer’s attention to Hutchins’s book. Other works from which Cramer may have obtained materials were Gilbert Imlay’s _North America_, published in London in 1797, and Jedidiah Morse’s _The American Gazeteer_, originally published in London in 1789 and republished in Boston in 1797. It is generally supposed that the first edition of the _Navigator_ was published in 1801, yet no copy bearing that date is known to be in existence. There are extant several copies of the edition of 1802. This edition was called _The Ohio and Mississippi Navigator_. In the preface dated February, 1802, the statement was made that two former editions had been issued; that they were both confined to the navigation of the Ohio River; and that they were sold in a very short time. No notice appeared in the _Pittsburgh Gazette_ or the _Tree of Liberty_ advertising either of the two earlier editions. The first mention of the _Navigator_ appeared in the _Pittsburgh Gazette_ on February 26, 1802. This notice stated that there was “In the press and speedily will be published by Zadok Cramer, ‘The Navigation of the Monongahela, Allegheny, Ohio, and Mississippi Rivers.’” The advertisement was continued in several succeeding issues of the paper. Then on March 13, 1802, the _Tree of Liberty_ announced that there had been published the day before, “The Navigation of the Monongahela, Allegheny, and Ohio Rivers.” The notice continued, “and in a few days will be added ... the ‘The Navigation of the Mississippi (with an account of the Missouri).’” No other notices appeared at or about this time conveying other information. As the edition of 1802 was called the _Ohio and Mississippi Navigator_, and the advertisement in the _Tree of Liberty_, referred to the publication of the “Navigation of the Monongahela, Allegheny, and Ohio Rivers,” nothing being said of the Mississippi, it might be inferred that it referred to one or both of the earliest editions and that they were published in 1802. The preface to the various editions of the _Navigator_ published after 1802, declared